
Dunbar, Seymour 1866-1947 A History of Travel in America, Showing the Development of Travel and Transportation From the Crude Methods of the Canoe and the Dog-sled to the ... Narrative of the Human Experiences And...; 1

Dunbar, Seymour 1866-1947 A History of Travel in America, Showing the Development of Travel and Transportation From the Crude Methods of the Canoe and the Dog-sled to the ... Narrative of the Human Experiences And...; 2

Guthnick, Paul Ein Universalinstrument für lichtelektrische Helligkeitsmessungen an Himmelsobjekten: 1947,2